关键词: 旋转爆震发动机；爆震波；传播特性；不稳定现象；实验

Abstract: Experimental research on unstable propagation phenomenon of rotating detonation wave was carried out on a model rotating detonation engine with 60mm inner diameter and 70mm outer diameter using hydrogen and air as propellants. Detonation was initiated by a tangentially mounted pre-detonator， which emitted a detonation wave into the rotating detonation engine. Pressures and propagation processes of detonation waves were measured by dynamic pressure sensors and high speed camera， respectively. Under stable case， the detonation velocity is 1680.6m/s (83.9% of the theoretical value) and operating frequency is 7642Hz. However， the detonation velocity exhibited strong instability with low mass flow rate， which can vary from 790.1m/s (39.4% of the theoretical value) to 1533.9m/s (76.6% of the theoretical value). In experiments it was found that during the detonation initiation process there is unstable phenomenon， including rotating direction changing， wave number changing from one to two， and two waves impinging. In this research it was also found that the direction of rotating detonation waves is random without a nozzle throat. However， in contrast when there is a nozzle throat， the direction trends to be regular. The possible reason for the unstable phenomenon mentioned above is that during the detonation initiation process， the initial flow field inside the rotating detonation engine is chaotic and very turbulent， so detonation initiation process can be easily disturbed by this random flow.

Key words: Rotating detonation engine；Detonation wave；Propagating properties；Unstable phenomenon；Experiments